The most reasonably priced component used on the Cr125r 1988 (j) European Direct Sales Expansion Chamber (4) is the Bolt,recessed,5x1.
The sub assemblies and components that make up this Expansion Chamber (4) include this Chamber Comp.exp., the most expensive part.
A sample from the products for the Expansion Chamber (4) include: Stay,rr.chamber, Washer,plain,5mm, Bolt,flange,6x28, Stay,silencer.